Mechanical and tribological properties of TiC-based composites for ED machining

Purpose: The goal of this work is comparative study of TiC-(Mo, Ni) composites with different TiC-phase content to obtain material with an optimal mechanical and tribological properties, which can be easy shaped by Electro Discharge Machining (EDM). Design/methodology/approach: Three variants of TiC-(Mo, Ni) composites with the different hardening phase to the bonding phase ratio were sintered in vacuum. The influence of the initial TiC hard phase content in the sintered composites on their mechanical and tribological properties as well as ED machinability were investigated. The density, Young modulus, hardness, fracture toughness were measured. Tribological tests were carried out conducted using "pin-on-disc" and "ball-on-disc" methods. Wire Electro Discharge Machining (WEDM) performance preliminary test were realised also. Findings: The microstructure of sintered TiC-(Mo, Ni) materials is characterized by a ring structure of carbides. Mechanical properties and wear resistance are better for samples with higher TiC content. All variants of investigated materials are characterized by good WED machinability. Research limitations/implications: Obtained materials are characterized by good mechanical, tribological and working properties but homogeneity of microstructure should be improved. Farther works will be continued also for limitation of the metallic phase content up to 5 vol. %. Practical implications: After additional technological evaluation tests, obtained materials could be used for the different parts of machines and wear components (e.g. nozzles, plungers) shaped by EDM. Originality/value: New type of TiC-metal bonded composite with high content of hard phase which could be shaped by EDM.